For the past several years, my colleagues and I have studied the consequences of exposure to aversive events which the organism cannot control. Dogs, rats, and humans exposed to inescapable and unavoidable aversive events later fail to learn to escape that aversive event in a different situation in which escape is possible, while subjects initially exposed to escapable aversive events do not fail to learn. This effect has been called the learned helplessness effect and has led us to develop a theoretical framework called the learned helplessness hypothesis. Although learned helplessness has received a great deal of theoretical attention and has been offered as an explanation for a variety of problems of human adaptation (e.g., reactive depression, chronic school failure, urban stress), the nature, limits, and causes of the learned helplessness phenomenon are largely unknown. The objective of the proposed research is to provide the missing data base. The limits, nature, and causes of the learned helplessness phenomenon will be explored. The research will use rats and will be directed at seven major questions: 1) What is the critical feature of the escape of "coping" response which prevents learned helplessness? 2) What are the crucial aspects of the test task that determine whether learned helplessness will occur? 3) Can learned helplessness be brought under discriminative control? 4) What is the degree of generality and breadth of transfer of learned helplessness? Here a major sub-question is whether appetitive helplessness exists. 5) What is the nature and cause of immunization against learned helplessness? 6) What is the nature and cause of therapy for learned helplessness? 7) What is the relationship between learned helplessness and aggression? It is hoped that this research will provide a better understanding of the helplessness effect, or the factors that produce it, of the theoretical structures that can account for it, and of its possible applicability to the solution of human problems.